1. Field of Invention
The present invention relates to motors, and more particularly to a motor cover arrangement which can highly increase the motor's cooling effect, lower the motor's noise and decrease dust pollution of the motor's interior so as to prolong the service life span there of.
2. Description of Related Arts
A motor 1 converts electrical energy to mechanical energy wherein the motor 1 comprises a rotor 3 for transmitting mechanical work, electric circuit terminals 4 for inputting electrical energy, and an induction means 5 for generating magnetic field. As the electrical energy is input through the electric circuit terminals 4, a magnetic field is generated by the induction means 5 so as to generate magnetic force exerted on the rotor 3. The rotor 3 will be rotated through the magnetic field by means of the magnetic force and generate mechanical energy.
While the motor 1 converts electrical energy to mechanical energy, it generates heat energy as well. In order to prevent the motor 1 from overheating, the motor further comprises a cooling fan 6 coaxially mounted on a driving shaft 7 outwardly extended from the rotor 3. The rotor 3 is arranged to drive the cooling fan 6 to be coaxially rotated through the driving shaft 7 so as to suck the air from outside to cool down the heat generated in the motor 1.
In order to protect the motor, the conventional motor is disposed in a motor protective housing 8 for covering the motor 1, wherein the motor protective housing 8 comprises a motor shell 8a sheltered the motor 1 and a motor cover 8b coaxially mounted on a side of the motor shell 8b to cover the cooling fan 6. A plurality of ventilating holes 9 are provided on the end surface of the motor cover 8b so that air from outside can be sucked into the motor protective housing 8 by the cooling fan 6 through the ventilating holes 9 to achieve the cooling effect.
However, when the motor 1 is used in such a tough condition such as driving a saw blade of a cutting machine, saw dust will also be sucked into the motor 1 with air through the ventilating holes during operation. The motor 1 may be burned or permanent damage while the saw dust gradually accumulates to the rotor 3.